Mechanical lead pencil



. 1931- A. 'T. WEIL MECHANICAL LEAD PENCIL Filed Aug. 15, 1930 4 2L zk ATTORNEY Patented Dec. 15,1931 1 UNITED STATES PATENT oFFicE 1 ALBERT T. WEIL; OF UNION CITY, NEW JERSEY, ASSTGNOR TO AIJLERICANZLEAD PENCIL COMPANY, OF NEW. YORK, N. 1 A CORPORATION OF NEW YORK.

MECHANICAL LEAD r nncrn Application filed August 15, 1930. Serial No, 475,409.

elements will not cause movement thereof.

' and hence affect the adjusted position of the lead. The arrangement also holds the eraser element steady during its action. In addition,-the improvements'serve to hold the propelling elements steady in adjusted position i I at all times, preventing the lead from working back during use of the pencil by writing or erasing.

The improvements are accomplished without adding parts to or materially changing the design of the usual type of mechanical pencil. p 7

A further function of the improvements is to' fix the distance the lead will be advanced by a predetermined movement of the propelling element so that the movement of'the propelling element from one latched position to a second latched position will advance the lead a proper degree, ratherv than'carry it outward to such length that it is subject to breaking through normal pressure upon the pencil by a writer.

The further object of the invention will hereinafter appear.

The improvements will be described with reference to the accompanying drawings in which Fig. 1 is an enlarged plan view of the pencil partly-in longitudinal section and partly broken away, to show the, construction of the improvements;

Fig. 2 is a transverse section on the line 22, Fig. 1, omitting the shell 1 showing the parts in latched position, and

V Fig. 3 is a similar section showing the. parts in intermediate or unlatchd position. 1

Referring to the drawings, 1 indicates the r outer shell .orcasing of mechanical pencil tapered as usual at its forward end 1%. Within casing 1 is fitted a fixed sleeve 3 formed at its lower end with a conical tip 3%. lead 4 is disposed within tip 3m and in practice will be carried by an element propelled.

longitudinally of sleeve 3 vby any suitable The type of propelling mechanism actuated by r tation of a rotatable propelling tube'5.

Propelling tube 5 is adapted for rotation within 's'leeve3 and is held against endwise movement relatively tothe sleeve by the pro; vision of an internalbead 6 formed in sleeve 3 and fitted, into an annular channel 7 formed it in the propelling tube.

At its upper end the propelling'tube' is provided with a seat to receive an eraser 8', and the cap 9 may cover the eraser and alsosurround said seat. The propellingtube 5 above head 6 and channel? is non-cylindrical betweeirlatching positions. This follows because (referring to Figs. 2 and 8) sleeve 3 is formed with one or more inwardly extending wall sections, which sections may be in the form of protuberanceslO as shown in, the drawings'or any other inwardly projected surface parts as bar-like indentations, etc. The said inwardly extending surface deflects thenormally cylindrical wall of the propel ling tube and as a result causes the latter to exert spring pressure upon the sleeve 3. The friction thus resulting will, of itself, serve to holdthe propelling elements against rota tion during normal use of the pencil, but as a further latching-means, I have provided in the propelling tube a depression adapted to receive the inwardly projected surfaces of the sleeve when the propelling tube is rotated to, bring the two in register. In the present embodiment, I have provided opposed protuberances 10 in the sleeve and opposed dimple-like recesses 11 in the propelling tube, which recesses are so formed as to receive the beads when the propelling tube is rotated a quarter turn from the'position illustratedin Fig. 3 and assumes the position 7 shown in Fig. 2. It will benoted that when the lead has been worn down and'requires H propulsion, a half turn of the tube willcarry the recesses 11 away from the protuberances, the sleeve 3 yielding for this purpose, and the protuberances will again be seated in the recesses at the end of the half turn thus prothe length of point, and thus assures rigidity in the lead during use of the pencil. It also enables use of the eraser without derangement of the adjustment of the lead.

Having described my invention, what I claim and desire to secure by Letters Patent is as follows 1. In a mechanical pencil, a sleeve and a propelling tube disposed therein for rotation, the sleeve being formed with: an internally projected wall section and the tube being formed with a seat to receive said wall section, the internally projected Wall section and seat being so propelled that the wall section passes into and out of register with the seat upon a rotation of the tube.

2. In a mechanical pencil, a sleeve, a propelling tube disposed within the sleeve for rotation, means holding the propelling tube against endwise movement relatively to the sleeve, means carried by the sleeve and acting upon the wall of the tube to deflect the tube from cylindrical to non-cylindrical shape, said tube being recessed so that upon predetermined rotation of the tube, the deflecting means is received by the tube to enable its return to cylindrical shape.

3'. In a mechanical pencil, a sleeve and a propelling tube disposed within the sleeve, one of said members being provided with a wall projection and the second member being provided with a socket to receive said projection, the arrangement being such that relative rotation Will carry the Wall and socket 35, out of and into register and the two in register will serve as latching members to prevent too free relative rotation.

4. A mechanical pencil comprising a sleeve and a propelling tube within the sleeve, and means carried by the sleeve which serves tochange the normal cylindrical form of the tube to non-cylindrical form thereby preventing too free rotation of the propelling tube.

In testimony whereof, I have signed my 45 name to this specification.

ALBERT T. WEIL. 

